United States

[last update: 2010/06/09]

The United States has the most comprehensive historical
climate records of any area on the Earth. The US National Oceanic and
Atmospheric Administration (NOAA) maintains the Global Historic Climate
Network (GHCN) used as the basis for world temperature calculations by
various agencies.

More temperature measurement stations exist in the US than
any other country or area of the world (about 30 percent of the world’s
stations historically and about 50 percent at present). The following figure
shows the location and density of stations in the world.

The following figure shows the number of stations in the
GHCN database with data for selected years, with the number of stations in
the United States (blue) and in the rest of the world (ROW – green). The percents indicate the percent of the total number of stations that are in the
U.S.

National Temperature
Trend

The station data are processed by NOAA, GISS and NCDC
using various adjustment methods.

The following figure compares the GISS data and the NCDC
(changed to green with black points). The NCDC shows lower temperatures in
the 1930s-1940s compared with the GISS data (indicated in blue circle). NCDC
also has higher temperatures in the late 1990s-early 2000s (indicated in the
magenta circle) since they are still using what NASA terms “flawed analysis”
as indicated on the GISS plot shown initially.

The following figure from the IPCC AR4 provides the
results of models for North America (pink= models with CO2, blue= models
without CO2, black= observed average). This indicates that prior to 1970 the
climate models can reproduce the historical temperature without using
anthropogenic CO2. Combining the IPCC model plot and the GISS US temperature trend
yields the plot on the right. The IPCC North America includes Canada and thus
shows more warming in recent decades due to the influence of the Arctic. The
US trend is within the natural forcing band until 1980.

The following figure superimposes the GISS US temperature
data for comparison with the global average. The US experienced considerable
warming in the 1903s compared to the global average.

Regional
Temperature Trends

The following figure shows the average annual temperature
trend for several regions within the United States (the data is from the
Hadley Climatic Research Unit CRUTEM3 database (used by the IPCC), plotted at
http://www.appinsys.com/GlobalWarming/climate.aspx).
Hadley data does not exclude urban station data which are influenced by the
increased amounts of concrete and pavement. Their data is also adjusted using
an unpublished process and then averaged for 5x5 degree grids. For most
areas of the US no statistically significant warming has occurred since the
1903s.

The actual warming has not been as much as indicated above
since the HadCRU data adjustment introduces artificial warming. The following
figures compare the HadCRU CRUTEM3 data with the NOAA GHCN station data for
one 5x5 degree grid: 40-45N x 70-75W (as indicated in the red rectangle on
the map). The left figure is the CRUTEM3 data, the right figure is the
average of all 56 long-term stations in the NOAA GHCN data. The next figure
below compares the two with the HadCRU data changed to red for comparison.
Hadley has artificially increased the warming in the data (or excluded
stations that don’t show warming).

Combining the above two graphs:

HadCRU CRUTEM3
data v NOAA
GHCN data

The following table shows some closer looks at a few
regions in the US. For warming to be significant in terms of anthropogenic
global warming, it must be statistically significant within the “CO2 Era” –
that is, since 1970, because the models can explain all warming prior to that
using only natural climate forcings.

United
States – West Coast

No Significant Warming
in the CO2 Era

United
States – Texas

No Significant Warming
in the CO2 Era

United
States – Southeast

No Significant Warming
in the CO2 Era

United
States – Midwest

No Significant Warming
in the CO2 Era

NASA /
GISS Deception

The GISS periodically publishes average US temperatures, which
include their adjustments. Adjustment methods are sometimes changed by the
agency. The following graphs show the historical US data from the GISS
database as published in 1999 and 2001. The graph on the left was produced in
1999 (Hansen et al 1999 [http://pubs.giss.nasa.gov/docs/1999/1999_Hansen_etal.pdf]); the graph on the right was produced in 2000 (Hansen et al 2001 [http://pubs.giss.nasa.gov/docs/2001/2001_Hansen_etal.pdf]).
They are from the same raw data – the only difference is that the
adjustment method was changed by NASA in 2000.

U.S. Temperature Changes Due to
Change in Adjustment Methods (Left: 1999, Right 2001)

The following figure compares the above two graphs,
showing how an increase in temperature trend was achieved simply by changing
the method of adjusting the data. Some of the major changes are highlighted
in this figure – the decreases in the 1930s and the increases in the 1980s
and 1990s.

Comparison of U.S. Temperature
Changes Due to Change in Adjustment Methods

NOAA provides a summary of the adjustments made to the
USHCN temperature data as shown in the following figure. [http://www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html]
The report states: “The
cumulative effect of all adjustments is approximately a one-half degree
Fahrenheit warming in the annual time series over a 50-year period from the
1940's until the last decade of the century.” This is similar to the
total amount of warming “observed”.

Average Total Warming Created by
Adjustments to USHCN Data

NOAA / CPC
Deception

The NOAA Climate Prediction Center (with “Vision: To be
the world’s best and most trusted climate service center”) provides the
following graph [http://www.cpc.noaa.gov/charts.shtml].
Although the US has data going back to the late 1800s, the CPC does not
provide any other graphs than trends starting in 1976.

The reason for the selection of 1976 as the start year for
trend calculation is shown below. By selectively ignoring the cyclical nature
of the temperature trends, one can create a false impression of warming.

The following figure shows the annual mean temperature
anomalies averaging the two 5x5 degree grids covering the coast of Oregon and
Washington from 1900 to 2007. This data is from the Hadley Climatic Research
Unit (HadCRU) as used by the IPCC. The warmest year was 1934. The CPC gives
the deceptive impression of warming in this area.

The following figures are from the above report. The top
figure shows rural unadjusted data , while the next figure shows urban
unadjusted data.

The NCDC then artificially creates warming at rural
stations through their data adjustments. The following figure shows the
adjusted rural data – it now has almost the same trend as the urban data.

A March 31, 2007 Science Daily article “Climate Data Shows
California Has Been Heating Up” reporting on a NASA study [http://www.sciencedaily.com/releases/2007/03/070330221144.htm]
provides some moderation to the GHG scenario: “Their objective was to shed new
insights into the relative roles humans and natural climate events play in
affecting California regional temperatures… (using air temperature patterns
from 1950 to 2000 )…Climate change
models and assessments often assume global warming's influence here would be
uniform. That is not the case. If we assume global warming affects all
regions of the state, then the small increases our study found in rural
stations can be an estimate of this general warming over land. Larger
increases would therefore be due to local or regional changes in land surface
use due to human activities… The largest temperature increases were seen in
the state's urban areas … Rural, non-agricultural regions warmed the least." Note on the individual
station graphs that for rural areas, that the selection of starting year (in
the study case 1950) can affect the trend. The study’s careful selection of
1950 allows it to ignore the previous warm decades of the 1930’s -1940’s.

Another example comparing urban and rural stations is
shown below for Seattle and Winthrop, Washington.

:

The following figure from the NOAA CPC shows the average
rate of temperature trend change since 1976 [http://www.cpc.noaa.gov/trendusa.gif].
The temperature change has mainly been in the winter months – consistent with
the urban heat effect.

See the other regional summaries covering North America
for further examples of urban versus rural differences:

A study of extreme drought and precipitation in the US (United States Geological Survey (2004, March 10).
Research Links Long Droughts In U.S. To Ocean Temperature Variations) [http://www.sciencedaily.com/releases/2004/03/040310080316.htm] states: “researchers believe that such large and sustained shifts in U.S.
precipitation are linked with the natural variability of sea surface
temperatures, the mechanisms are not well understood and cannot yet be used
to help predict the likelihood of droughts. These sea surface temperature
variations are characterized by climatic indices dubbed the Pacific Decadal
Oscillation, or PDO, and the Atlantic Multidecadal Oscillation, or AMO.
McCabe and his coauthors suggest that large-scale droughts in the United States
are likely to be associated with positive AMO -- the kind of warming of sea
surface temperatures that occurred over the North Atlantic in the 1930s, 50s,
and since 1995.”

A study of past 1930s-type dustbowl droughts (National Oceanic And Atmospheric Administration (1998,
December 21). Droughts More Severe Than Dust Bowl Likely) [http://www.sciencedaily.com/releases/1998/12/981221083346.htm]
states: “The
authors found a greater range of drought variability in the past than found
in the instrumental record. Droughts of the 20th century have been only
moderately severe and relatively short, compared with droughts of much longer
ago. Woodhouse said that paleoclimatic records of the past 400 years
strongly indicate that the severe droughts of the 20th century, the 1930s
Dust Bowl and the l950s drought, were not unusual events and suggest that we
can expect to have droughts of this magnitude once or twice a century.”

There are always some areas in the US that are
experiencing drought or extreme wet, as indicated in the above two figures.
The following figure shows the change in drought severity from Sep 2007 to
Aug 2008. Drought in southern California and Arizona has lessened, while
drought in Texas and Georgia has worsened.

The following figure shows northern hemisphere snow cover
for late January from 1967 to 2008.

The National Institute of Environmental Health Sciences
published the following figure in 2003 (Davis et al, “Changing Heat-Related
Mortality in the United States” [http://ehp.niehs.nih.gov/members/2003/6336/6336.html]).
The report states: “We
calculated the annual excess mortality on days when apparent temperatures--an
index that combines air temperature and humidity--exceeded a threshold value
for 28 major metropolitan areas in the United States from 1964 through 1998.
Heat-related mortality rates declined significantly over time in 19 of the 28
cities. For the 28-city average, there were 41.0 ± 4.8 (mean ± SE) excess
heat-related deaths per year (per standard million) in the 1960s and 1970s,
17.3 ± 2.7 in the 1980s, and 10.5 ± 2.0 in the 1990s. In the 1960s and 1970s,
almost all study cities exhibited mortality significantly above normal on
days with high apparent temperatures. During the 1980s, many cities,
particularly those in the typically hot and humid southern United States,
experienced no excess mortality. In the 1990s, this effect spread northward
across interior cities. … Heat-related mortality has consistently declined
on a decadal basis (Figure 2). In 19 of our 28 study cities, total annual
heat-related (population-adjusted) mortality was statistically significantly
lower in the 1990s than in our 1960s-1970s decade. … In the United States
and other countries, mortality is higher in winter than in summer”

There is also no relationship between global warming
and flood deaths.

Hurricanes

The following figure shows the Accumulated Cyclone Energy
(ACE) to 2007 for the North Atlantic basin. The ACE provides a measure of
total hurricane intensity over the year.

The following figure shows a plot of the Atlantic
Multidecadal Oscillation (AMO) (see www.appinsys.com/GlobalWarming/PDO_AMO.htm
for details about the AMO), along with the above North Atlantic ACE
superimposed on the AMO plot. The correlation is clear.

[http://tropical.atmos.colostate.edu/Forecasts/2008/nov2008/nov2008.pdf]
the authors state: “Despite
the global warming of the sea surface that has taken place over the last 3
decades, the global numbers of hurricanes and their intensity have not shown
increases in recent years except for the Atlantic. This large increase in
Atlantic major hurricanes is primarily a result of the multi-decadal increase
in the Atlantic Ocean thermohaline circulation (THC) that is not directly
related to global sea surface temperatures or CO2 gas increases. Changes
in ocean salinity are believed to be the driving mechanism. These
multi-decadal changes have also been termed the Atlantic Multidecadal
Oscillation (AMO).”

The following figure is from the above mentioned Klotzback
/ Gray study and shows tracks of major (Category 3-4-5) hurricanes during the
25-year cooling period of 1945-1969 versus the 25-year warming period of
1970-1994. They state: “CO2
amounts in the later period were approximately 18 percent higher than in the
earlier period. Major Atlantic hurricane activity was less than 1/2 as
frequent during the latter period despite warmer global temperatures.”

Tracks of major (Category
3-4-5) hurricanes during the 25-year cooling period of 1945-1969 versus the
25-year warming period of 1970-1994

CO2
Emissions

A study published in 2008 reports that China (which was
excluded from the Kyoto requirements) became the largest emitter of CO2 from
fossil fuel combustion and cement production in 2006. (Gregg, J. S., R. J.
Andres, and G. Marland, “China: Emissions pattern of the world leader in CO2
emissions from fossil fuel consumption and cement production”, Geophysical Research Letters35,
2008) [http://www.agu.org/pubs/crossref/2008/2007GL032887.shtml]. The following
figures are from that study. The left-hand figure compares the US annual
carbon emissions with China’s since 1950. The right-hand figure compares the
monthly carbon for 2001 – 2007. The study states: “the annual emission rate in the
US has remained relatively stable between 2001–2006 while the emission rate
in China has more than doubled.”

(USA Today, May 6, 2010) – “Energy-related
carbon dioxide emissions fell a record 7% last year, due partly to the
economic downturn, the U.S. government reported Wednesday. While emissions
have fallen in three of the last four years, 2009's drop was the largest
since the U.S. Energy Information Administration (EIA) began keeping
comprehensive data in 1949. The report comes as the U.S. Senate is gearing up
to consider a possible climate bill that would require a reduction in
greenhouse gas emissions. … "The large decline in emissions was driven
by the economic downturn, combined with an ongoing trend toward a less
energy-intensive economy and a decrease in the carbon-intensity of the energy
supply," said Richard Newell, head of EIA, a data-analysis section
of the Department of Energy. ” [http://content.usatoday.com/communities/greenhouse/post/2010/05/us-carbon-dioxide-emissions-fell-record-7-last-year/1]

The following figure shows the
net flux of carbon to the atmosphere due to land use change (which results
mainly due to deforestation for agriculture and fuel-wood in the tropics and
reforestation in the US). The United States has the largest land use
change carbon sink in the world – i.e. while much of the world is burning its
forests, the US is absorbing the carbon from the atmosphere. This figure
shows: “Cumulative
Emissions of C02 From Land-Use Change measures the total mass of carbon
absorbed or emitted into the atmosphere between 1950 and 2000 as a result of
man-made land use changes (e.g.- deforestation, shifting cultivation,
vegetation re-growth on abandoned croplands and pastures). Positive values
indicate a positive net flux ("source") of CO2; for these
countries, carbon dioxide has been released into the atmosphere as a result
of land-use change. Negative values indicate a negative net flux
("sink") of CO2; in these countries, carbon has been absorbed as a
result of the re-growth of previously removed vegetation.” [http://earthtrends.wri.org/pdf_library/maps/co2_landuse.pdf].

The same report also states: “While the majority of global CO2
emissions are from the burning of fossil fuels, roughly a quarter of the
carbon entering the atmosphere is from land-use change.”